The present invention relates to a vehicle sunroof system, and in particular to a vehicle sunroof system provided with an improved inner frame structure supporting the slide mechanism for a moveable sunroof panel.
A vehicle sunroof system is typically provided with a moveable sunroof panel that can slide in a fore-and-aft direction to open and close a roof opening formed in a fixed roof panel of the vehicle. Typically, an inner frame including a pair of side frame members and a front frame member extending between the front ends of the side frame members is provided under the fixed roof panel as disclosed in Japanese Utility Model Laid Open Publication (Kokai) No. 7-40231. These frame members extend along the periphery of the roof opening, and are typically made of extruded aluminum alloy. The front frame member is provided with a front drain groove, and each side frame member is provided with a side drain groove and a guide rail for guiding the sliding movement if the moveable roof panel.
In such an arrangement, it is important to prevent moisture from entering not only the passenger compartment but also the guide rails and other parts of the mechanism for actuating the sunroof system. In particularly when the guide rail is formed as a part of an extruded side frame member, the front end of the guide rail remains exposed, and this could allow the intrusion of water into the guide rail.
Japanese Patent Publication (Kokoku) No. 5-23208 discloses an inner slide type sunroof system incorporated with a tilt mechanism. In the invention disclosed in the prior patent publication, a lock lever is pivotally supported by each front slider of the moveable panel, and an engagement projection provided at one end of this lock lever is adapted to engage an engagement hole formed in the corresponding side frame member to fixedly secure the moveable panel against the fore-and-aft movement except when the moveable panel is tilted down and slid rearward. In this lock lever arrangement. when the rear end of the moveable panel is lowered (tilted down), the other end of the lock lever is pushed down by the lower surface of the moveable panel and the engagement projection is lifted out of the engagement hole so that the moveable panel is thereby allowed to be slid rearward. Conversely, when the rear end of the moveable panel is raised to achieve the fully closed state of the moveable panel or further upwardly to achieve the tilted up state, the other end of the lock lever is disengaged from the lower surface of the moveable panel, and the engagement projection of the lock lever again fits into the engagement hole so that the moveable panel is firmly locked against any fore-and-aft movement.
However, when the side frame member is made of aluminum alloy which is relatively soft, the repeated engagement of the engagement projection with the engagement hole could cause excessive wear to the engagement projection, and this would lead to the generation of undesired rattling noises due to inadequate restraint of the moveable panel. It is conceivable to provide a separate member made of more wear resistant material for defining the engagement hole or to use a harder material for the side frame member, But, in either case, the manufacturing cost inevitably rises.
Tilting down of the moveable panel preceding the rearward sliding movement of the moveable panel is typically effected by engaging a lateral pin shaft provided in the rear slider in a cam slot formed in a side plate depending from the moveable panel and provided with a corresponding cam profile. However, a certain play is inevitable between the lateral pin shaft and cam slot, and this, combined with the plays in other parts of the related mechanism, could cause undesired rattling noises during the opening and closing operation of the sunroof system.
Typically, such a moveable panel is provided with front and rear sliders that are guided by the guide rails and is actuated by a push-pull cable attached to the rear sliders and driven by an electric motor. When closing the moveable panel, the push-pull cable is pushed until the moveable panel is fully closed. The fully closed position of the moveable panel is most often defined by a mechanical stop which limits the forward movement of the front sliders, and the push-pull cable tends to be abruptly compressed because of the inertia of the electric motor when the moveable panel comes to a stop. This abrupt compression of the push-pull cable could induce a buckling of the push-pull cable which would strike the cable against the sheath tube thereof or any other member adjacent to the push-pull cable, and thereby cause undesired noises.
Also, the mechanical stop that limits the forward movement of the front sliders must be capable of withstanding a substantial force, and the need for such a member not only increases the manufacturing cost but also requires an extra mounting space which is detrimental to the compact design of the sunroof system.
As the moveable panel tilts down and slides rearward, a guide pin provided in the side plate is guided downward and then rearward by a guide member defining a curved guide slot, and moves along an upper guide slot of the guide rail while the rear, slide is guided along a lower guide slot of the guide rail. Because the upper and lower guide slots are provided adjacent to each other, when the guide member is fitted into the guide rail, and the curved guide slot defined in the guide member is aligned with the upper guide slot, the guide member interferes with the lower guide slot. Therefore, the rearward movement of the front slider is limited by the guide member, and this limits the maximum stroke of the fore-and-aft movement of the moveable panel. This is not desirable because it is normally desired to maximize the opening area of the sunroof system, and the maximum stroke of the fore-and-aft movement of the moveable panel is therefore desired to be maximized.
A sunroof system is often provided with a wind deflector device that is deployed upward from the front edge of the roof opening to control the air flow into the passenger compartment and to prevent air flow noises. Typically, a deflector blade is supported by a pair of arms on either side and urged upward by a spring member so as to rise when the moveable panel is moved rearward and to be retracted as the moveable panel closes the roof opening. Japanese Utility Model Laid Open Publication (Kokai) No. 3-43024 discloses a support link mechanism for improving the support rigidity of such a wind deflector device. However, because the support link mechanism includes a support link member that extends obliquely from a front end of the moveable panel and the inner frame, the moisture On the moveable panel may drip along the support link particularly when closing the moveable panel, and may reach components of the sunroof system such as the guide rails. This is not desirable for the reliable operation of the sunroof system.
The base end of each deflector arm is pivotally supported by a side frame member. The side frame member is typically made of extruded aluminum while the deflector arm is made of stainless steel. Because the two parts made of different metals are in contact with each other, galvanic corrosion is induced. This could accelerate the corrosion of the side frame member and severely impair the durability of the sunroof system.
The side frame members of the inner frame are each provided with a drain groove and each terminal end of the drain groove is provided with a drain water outlet to expel water out of the vehicle. Typically, a hose is used for guiding water from the corresponding water drain outlet. Therefore, when a large amount of water is required to be released, such as when the vehicle accelerates or decelerates, the water flow fills the entire cross section of the internal passage of the drain water outlet member, and is prevented from flowing as smoothly as required because of the air trapped in the passage. In such a case, the water could overflow from the drain groove, and could even spill into the passenger compartment or into the guide rail. This could be avoided by increasing the size of the internal passage and the inner diameter of the hose, but this requires a larger space for accommodating such an increase in size, and increases the manufacturing cost.
In view of such problems of the prior art, a primary object of the present invention is to provide an improved sunroof system having a favorable inner frame structure that is incorporated with guide rails and drain grooves.
A second object of the present invention is to provide an improved sunroof system which is free from rattling and other noises.
A third object of the present invention is to provide an improved sunroof system which is durable and economical.
A fourth object of the present invention is to provide an improved sunroof system which is suited for compact design.
A fifth object of the present invention is to provide an improved sunroof system which allows a relatively large stroke to the fore-and-aft movement of the moveable panel.
A sixth object of the present invention is to provide an improved sunroof system which can prevent moisture from dripping or otherwise entering the passenger compartment and the sunroof actuating mechanism.
A seventh object of the present invention is to provide an improved sunroof system which can allow moisture to be drained rapidly from the drip groove of the inner frame structure.
According to the present invention, such objects can be accomplished by providing a vehicle sunroof system, comprising a fixed roof panel defining a roof opening; an inner frame surrounding the opening under the fixed panel in a spaced relationship, the inner frame comprising a pair of side frame members and a front frame member extending between front ends of the side frame members; a pair of guide rails supported by the side frame members and extending in a fore-and-aft direction along either side of the roof opening, each of the guide rails being provided with a bottom wall and a pair of upright walls; a moveable panel slidably supported by the guide rails to selectively open and close the roof opening; and a terminal member attached to each front corner part of the inner frame; the terminal member comprising a vertical wall closing a corresponding end of a channel defined by the bottom wall and upright walls.
The front end of each guide rail is closed by the terminal member, and moisture or other foreign matter is prevented from getting into the guide rail. Preferably, each of the side frame members comprises a side drain groove extending along either side of the roof opening and the front frame member comprises a front drain groove communicating with front ends of the side drain grooves. Each of the upright walls may extend from a corresponding one of the side frame members while the bottom wall is defined by the side frame member.
According to a preferred embodiment of the present invention, the moveable panel is provided with a plurality of sliders that are guided by the guide rails, and at least one of the sliders pivotally supports a lock lever having an engagement projection at an end thereof, the terminal member being provided with an extension defining an engagement hole for receiving the engagement projection of the lock lever.
Thus, by selecting suitable material for the terminal member that serves the purpose of closing an end of the guide rail, the terminal member may also provide a highly wear resistant engagement hole for the lock lever, and this improves the durability of the sunroof system. The bottom wall of the guide rail may be provided with an opening aligning with the engagement hole so that the engagement hole may be provided in the center of the guide rail, and the moveable panel can be thereby even more firmly retained.
When the engagement hole is surrounded by a bead which fits into the opening in the bottom wall of the guide rail, the positioning of the terminal member with respect to the side frame member can be facilitated. If the opening in the bottom wall of the guide rail is provided with a rectangular or other non-circular shape, the terminal member is prevented from turning during the assembly process even when a threaded bolt is used for attaching the terminal member to the inner frame, and the assembly work is simplified.
Typically, the moveable panel is provided with a plurality of sliders that are guided by the guide rails. In such a case, the terminal member may additionally defining a stopper surface for defining a limit of a forward movement of one of the sliders, preferably via an elastic member, so that the number of component parts can be reduced, and the necessary mounting space may be reduced. As the terminal member can thus perform two or more functions by itself, a significant reduction in the manufacturing cost can be achieved.
An automotive sunroof system is often fitted with a wind deflector device comprising a deflector blade, and a pair of deflector arms supporting either end of the deflector blade at free ends thereof. In such a case, a base end of each of the deflector arms may be pivotally attached to a bottom surface of the side drain groove of the corresponding side frame member. Thus, the front drip groove and side drip grooves conveniently provide recesses for receiving the deflector blade and deflector arms in the retracted state of the deflector device so that the deflector device would not substantially increase the height of the overall sunroof system.
To avoid galvanic corrosion and improve the durability of the sunroof system, the base end of each of the deflector arms may be pivotally attached to the bottom surface of the side drain groove via an electrically insulating base member such as a plastic member. Also, for the same reason, a sheet spring for upwardly urging each deflector arm may be provided with a base end attached to the base member and a free end engaging the deflector arm.
To increase the support rigidity for the deflector blade, the deflector device may further comprise a support link member having a free end pivotally attached to the deflector blade and a base end engaged by a slot formed in a vertical portion extending from the terminal member to define a limit of an upward movement of the deflector blade. Thereby, the terminal member is enabled to perform yet another function. The support link member nay be provided with a rib for guiding moisture onto the front drain groove and thereby prevent intrusion of moisture into the passenger compartment or the guide rail structure.
To effect the tilt motion of the moveable panel, various mechanical components are interposed between the moveable panel and the inner frame. Therefore, plays between such mechanical components could cumulatively cause rattling or other noises. To avoid this problem, each of the rear sliders may be allowed to define the tilt down position of the moveable panel by engaging a part of the corresponding side plate via a resilient member. The resilient member produces a biasing force which tends to fill the plays that may exist between the mechanical components.
According to a preferred embodiment of the present invention, the upper guide slot and lower guide slot are provided with a lower wall and an upper wall, respectively, which are separated from each other. According to this arrangement, interference between the upper and lower guide slots is minimized, and this contributes to compact design of the sunroof system. This is particularly advantageous in the case of a tilt down mechanism in which as the moveable panel tilts down and slide rearward, a guide pin provided in the side plate is guided downward and then rearward by a guide member, and moves along an upper guide slot of the guide rail while the rear slide is guided along a lower guide slot of the guide rail. Because the guide member can be fitted into the upper guide slot without interfering with the lower guide slot, the rearward movement of the front slider is not obstructed by the guide member, and the stroke of the fore-and-aft movement of the moveable panel can be thereby maximized,
According to a preferred embodiment of the present invention, the moveable panel is provided with a pair of side plates each carrying a front slider and a rear slider that are guided by the guide rail, and actuated by a push-pull cable connected to one of the rear sliders. In such a case, the guide rail may include a guide slot for receiving the push-pull cable while a front end of the guide slot for the push-pull cable being provided with a resilient stopper member for resiliently defining a limit of a forward travel of the push-pull cable before a forward movement of the moveable panel is mechanically limited by a part of the inner frame. By thus resiliently limiting the forward movement of the push-pull cable and avoiding an abrupt axial compression of the push-pull cable, the abrupt buckling of the cable can be avoided and hence the associated noises that would be otherwise caused by the buckling cable striking the adjacent wall can be avoided.
According to another aspect of the present invention, the sunroof system further comprises a drain outlet member attached to a rear end of each of the side drain grooves, the drain outlet member internally defining a drain outlet passage which communicates with the side drain groove and is divided by a partition wall into an upper air passage and a tower drain water passage. Because the passage in the drain outlet member would not be entirely filled by water as drain water is being expelled from the side drain groove of the side frame member out of the vehicle, and the air trapped in the drain outlet member is allowed to escape to the inlet end of the drain outlet member, the water can be all the more quickly expelled. According to a preferred embodiment, the drain outlet member comprises an inlet opening communicating with the side drain groove, a hose coupler and an internal passage communicating the hose coupler with the inlet opening, the internal passage being divided by the partition wall into the upper air passage and lower drain water passage. The drain outlet member can be made most conveniently by injection molding plastic material when the partition wall extends laterally across the internal passage of the drain outlet member.